Control device for alarm mechanism



Dec. 20, 1932 c P HQWARD 1,891,540

CONTROL DEVICE FOR ALARM MECHANISM Filed May 19, 1931 2 Sheets-Sheet l D86. 20, c p HOWARD CONTROL DEVICE FOR ALARM MECHANISM Filed May 19, 1951 2 Sheets-Sheet 2 55 I v 1 I A 54 L /I 11/ .4/ I 77 '72 7,? 59 70 65 62 7 Z 70 30%; 4 i V A rrrrrrr H Patented Dec. 20, 1932 CLIFTON r. nowAnD, or woncnsrna, MASSACHUSETTS, Assienonro' nocxwoon SPRINKLER (IQIVIIA'NY OF MASSACHUSETTS, A CORPORATION OF MASSACHUSETTS coN'raoL nnvron FOR ALAnivr MECHANISM,

Application filed May 19, 1931. SerialNo. 538,493.

This invention relates to signal systems.

designed to sound an alarm upon the occurrence of excessive atmospheric temperatures in a defined area. Such systems may be in- 5 stalled in places where sprinklers cannot be used, or may be supplementary to the sprinkler system. 9

It is the general object of my invention to. provide an improved control device for the alarm mechanism of such signal systems, so designed that the control device will be reli ably responsive to excessive atmospheric temperatures, A A further object of the invention is toprovide a control device which may be assembled on a cover plate toran ordinary junction box,

such as is commonly used in electric wiring installations.

p I also provide which is adapted for installation where head room is limited; I i

My invention further relates to arrange ments and combinations of parts whichwill be hereinafter.described and more particularly pointed out in the appended claims. p

Two forms or the invention are shown in thedrawings, in which I I Fig. 1 is aside elevationofone form of my improved control device 7 Fig. 2 is a sectional elevation thereof, taken along the line 22 in Fig. 1';

Fig. 3 isa plan View of the cover and parts supported thereby,taken along the line 3-3 inFig.2; I

Fig. 4; is a sectional view similar to Fig. 2 but showing the parts released;-

Fige shows-a slight modificationof the. contact members;

40 Fig. 5 is a side elevation of a modified construction; i i i Fig. 61s an end view, looking the direc-.

tion of the arr-W6 in Fig. 1 Fig. 7 isa sectional side elevation, taken *5 along the line 7,7 in Fig. 6.;

' 16 may extend to a suitable signal device and a modified construction Fig. 8 is a transverse sectional iew, taken along the-line 88 in Fig.7 0

, Fig, 9 is a sectional elevation similar to Fig. 7 but showing the parts in a different position, and p e v Fig. 9 shows a modified arrangement of the contact members. i '3 Referring to Figs. 1 to 4, I have shown my improvedcontrol device assembled a cover plate 10, adapted to be secured to a 5 junction 130x11 by binding screws 12. The box 11 is of the usual commercialeonstruction, and pipes or conduits 14' may be connected thereto, through which wires 15 and to a source of electricity, not shown.

-My improved control device, as shown in Figs. 1 to 4;, comprises a ring ofinsu'lating. material, seated in a recessed portion 21 of the cover plate 10. A cup-shaped member 23 is mounted in the axial openingof the ring 20 and extends through an axial openmg in the cover plate 10. The outer end of the cupshaped member 23 is flanged or spun outwardly, as indicated at 25, thereby securing the ring 20, the cover plate 10 and the member 23 in permanently assembled relation and alignment.

Contact members 26 and 27 aremounted on the insulating ring 20 and are connected to the Wires 15 and 16 respectively. The cupshaped member 23 has tapered and threaded inner side walls to receive the tapered and threaded base portion30 of a frame or support 31 on which the heat-releasable parts of my invention are assembled.

A plunger 32is mounted in an opening or recess 33 in the base 30 and is provided with a coil spring 35 interposed between ashoulder 36 on the plunger32 and the bottom of the cup-shaped member 23. A cap 38 isheld against the open lower end of the base .30

a post 40, a lever 41, a locki11g-1ne1nber;formed in two parts 43 and 44 and a clamping stud 45.

The post is interposedbetweenthe outer '9 end of the cap 38 and the shorter end of the lever 41. The lever 41 is pivoted at an intermediate point on the inner end of the clamping stud 45 and is provided with arecess 46 to receive one end of the locking member 43. The second locking member 44 is interposed between a shoulder 47 on the member 43 and a shoulder 48 on the foot of the post 40. The parts 43 and 44 are normally secured in assembled relation by a portion of low melting fusible alloy or solder 49.

When the parts are assembled as shown in Fig. 2 and pressure is applied by the clamping stud 45, the cap 38 is pressed firmly against the open end of the base 30, forcing the plunger 32 inward and compressing the spring 35.

A double-flanged two-part insulating bushing 50 is inserted in an opening or slot 53 in the contact member 26 and is secured to the end of the plunger 32 by a binding screw 52.

When the parts are assembled, the inner flange of the bushing engages the contact member 26 and holds it spaced from the contact member 27. At this time the spring 35 is compressed by the pressure on the cap 38. If the temperature of the atmosphere surrounding the control device rises above a predetermined point, the solder 49 will melt, allowing the two parts 43 and 44 or" the locking member to swing apart and separate, thus releasing the cap 38 and allowing the plunger 32 to be moved by the spring 35 to the position shown in Fig. 4, with the contact members 26 and 27 engaging each other to complete the alarm circuit.

The composition of the low-melting alloy or solder 49 may be varied so that the device will respond to any selected temperature within aconsiderable range.

' From the above description, it will be evident that each control device is a separate unit adapted to be readily connected into a signal system wherever a junction box is installe When used in an open circuit system with the contact members 26 and 27 normally separated, as shown in Fig. 2, the several control devices will be connected in parallel, so that the closing of the circuit at any one of the devices will cause the alarm to sound.

The-device may be readily adapted for use on a closed circuit system by a slight change in the arrangement of the contact members, as indicated at 26 and 27 in Fig. 4", in which case the control devices will be installed in series, so that the opening of the circuit at any one of a number of difi'erentcontrol points will cause the alarm to sound.

In Figs. 5 to 9 I have shown a modified construction which is particularly adapted for use on ship-board or in any other places where head-room is limited. In this form of my invention, I provide a casing having a. removable cover plate 61.

A block 62 of insulating material is recessed at 63 to receive an internally threaded metal socket 64 which may be secured therein by screws 65. The outer end of the socket 64 extends throu h an opening in the cover plate 61 and is anged outwardly over the cover plate to firmly secure the block 62 and socket 64 in position on the cover plate.

The block 62 is also provided with asecond recess 66 and with a passage 67 connecting the recesses 63 and 66. Terminals or contact points 68 and 69 are mounted in the partition which separates the recesses 63 and 66 and are provided with binding screws 70 to which the wires of a signal circuit ma Y be connected.

A contact plate 7 2 is loose y mounted on the inner end of a plunger 74 but is fully insulated therefrom. The plunger 74 is provided with an insulating sleeve 76, slidable in the opening 67 previously described. A coilspring 77 tends to move the plunger outwardl in the socket 64 and to seat the contact plate 2 against the contact points 68 and 69, thus completing an alarm circuit.

The socket 64 is threaded to receive the base of a heat-controlled releasing mechanism which may be identical in construction with the mechanismpreviously described in connection with Figs. 1 to 4.

This mechanism includes a cap 80 engaging the outer end of the plunger 74 and holdin it normally in the inoperative position ind cated in Fig. 7. I

The cap 80 is held in position by a post 83, lever 84, locking member and adjusting stud 86, all as previously described. The locking member 85 is preferably formed in two separate pieces, secured together by a portion of low melting solder 87.

When pressure is applied by the stud 86, the cap 82 is pressed against the base 80 and plunger 74, and allparts are securely held in this position until a rise in temperature above a predetermined point melts the solder 87, allowing the two parts of the locking member 85 to separate. Such separation causes displacement of the lever 84 and post 83, whereupon the spring 77 pushes the plunger 74 outward through the base 80 and moves the contact plate 72 into position to complete the circuit between the contact point 68 and 69.

I have thus provided a very simple and compact circuit-closing construction, which takes up very little room and which may be conveniently used where space is at a premium.

If the device is to be used on a closed circuit system, the construction is slightly modified as shown in Fig. 9. This modification consists primarily in mounting the terminals and 91 in a cover plate 92 on the block 62, in-' stead of mounting them in the partition between the recesses 63 and 66,"as previously described.

\Vith this construction, the contact plate 72 engages the terminals 90 and 91 when the plunger 74 is forced inward by assembly of the parts. When the parts are released by a rise in temperature above a predetermined point, the plate 72 moves away from the terminals 90 and 91, thus breaking the circuit and soundingthe alarm, instead of closing the circuit for this purpose as inthe form previously described. I

This construction possesses many of the advantages of the construction shown in Figs. 1 to 4 and also requires substantially less head-room when used on ship-board or any places where head-room is limited.

Having thus described my invention and the advantages thereof, I do not wish to be limited to the details herein disclosed, otherwise than as set forth in the claims, but what I claim is 1. A control device to be supported by a junction box having a cover plate with an opening therethrough, said control device comprising a ring of non-conducting material aligned with said opening, a cup-shaped member extending through said ring and said opening and securing said ring and plate together, contact members mounted on said ring and at opposite sides of the opening therein, with one'of said membersextending outside of and across the bottom of said cupshaped member, a plunger extending through said cup and having a bearing in the inner end of saidcup, said plunger engaging said contact member, and means acting normally to force said plunger against said Contact, member and to thereby hold said contact means acting normally to force said plunger against said contact member and to thereby hold said contact members 1n a predetermmed relatlon, said latter meanscomprismg heatreleasable elements restraining said plunger and adapted to free said plunger when the temperature of the surrounding atmosphere reaches a predetermined point.

3. The combination in a control device as set forth in claim 2, in which the base portion of a supporting frame is secured in said cupshaped member, with said plunger extending through an opening in said base'portion, and said heat-releasable elements being mounted in and supported by said frame. I

4; The combination in a control device as set forth in claim 2, inwhich the base portion of a supporting frame is secured in said cupshaped' member, with said plunger extending through an opening in said base portion, and said heat releasable elements including a twopiece locking member mounted in and supported by an open portion of saidframe and being fully exposedto changes in sur rounding atmospheric conditions, the two parts ofsaid locking member being held together by fusible solder."

5. A controldevice comprising a casing, a cup-shaped member secured in said casing, said member being internally threaded and having an axial opening through the bottom thereof, contact members mounted in said casing and insulated from each other, an open frame member having a base portion fitting said threaded cup and havingan axial opening,a plunger slidable in said opening and engaging one of said contact members to hold said member in a predetermined rela-' tion with respect to the second contact member, means to move said plunger, and heatreleasable means to restrain such movement until the temperature of the surrounding atmosphere exceeds a predetermined limit.

6. The combination in a control device as set forth in claim 5, in which means is provided for positively connecting said plunger to its associated contact member.

I 7. The combination in a control device as set forth in claim 5, in which means is provided for positively connecting said plunger to its associated contact member, and in which additional means is provided forpreventing movement of the second contact member when engaged by the first contact member.

. 8. The combination in a control device as set forth in claim '5, in which said plunger is made of non-conductingmaterial, and in which said plunger-moving means comprises a spring surrounding said plunger and housed in the base portion of said open frame member.

. 9. A control device comprising a casing having a removable cover, a piece of insulating material mounted on said cover, contact members secured tosaid insulating material, a plunger slidable in said piece of insulating material, a contact plate mounted on said plunger, a spring tending to move said plunger axially and to thereby change the relation of said plate to said contact members, and heat-releasable elements restraining move- -ment of saidplunger by said spring, said elements including a member having parts thereof secured together by solder. and separable upon an excessive rise in temperature said contact plate bemgmsulated from said plunger and being effective to complete a circuit between said contact members when in engagement therew th.

10. The combmation in a control device as set forth in claim 9,in which the piece of insulating material is secured to the removable cover by aninternally threaded socket secured in said piece of material and also secured in an opening in said removable cover,

and which said heat-releasable elements are mounted on a base threaded into said socket and supported thereby and within which base said plunger is slidable.

In testimony whereof I have hereunto affixed my signature.

CLIFTON P. HOWARD. 

